Various products, usually of a pharmaceutical nature, are packaged in ampules which insure a perfectly hermetic seal and totally eliminate the possibility of evaporation of the contents or contamination thereof. The ampules are usually subjected to various procedures such as warming, flame-treating, pregasing, filling, after-gasing, rewarming, and finally sealing.
In order to lower unit cost of products packaged in ampules at least the filling and sealing operations are usually carried out in an automatic device having a pair of stations lying on a transport path. The succession of the ampules is displaced along the transport path from one station to the next. Since the operation must be carried out with a certain degree of precision the ampules are advanced stepwise, with the filling and sealing operations being carried out as the ampules are stopped in the respective stations.
The ampules are either advanced by so-called cells carried on an endless belt or chain, or by an advance rake having fingers that are reciprocated both in and parallel to the transport direction. The fingers of the rake each push along a single respective ampule a single step in the transport direction, then withdraw laterally from the transport path, move backward a step, and again move transverse to the transport direction behind the next succeeding ampule to similarly displace it one step forward.
It is frequently necessary during the heating and sealing of the ampules to rotate them about their own longitudinal axes. To this end a large drive roller covered with elastic material is provided adjacent each of the treatment stations which requires such rotation in order to insure proper treatment. For filling it is also necessary to provide adjacent each of the filling stations rather complicated centering devices, as the tips of the ampules frequently do not lie directly on their longitudinal axes. Thus these devices are often expensive and complicated.
In addition a frequent problem with such an automatic filling and sealing apparatus is breakage of the ampules. This is caused mainly by the brusque stepwise advance of the succession of ampules. In addition the manner in which they are fed into the transport path and the manner in which they are removed from this path is often relatively likely to cause breakage.
Another disadvantage of the known automatic filling and sealing machines is that they are very large. For instance in a known machine wherein four ampules are treated at a time in each treatment station the distance between the input and output ends of the transport path is 4 meters. Thus it is very difficult for a single person to oversee the operation of the machine at both the input and output ends, usually two operators being necessary for controlling the machine.